File:Popcorn Clouds along the Amazon River (MODIS).jpg

English: On August 26, 2023, The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured a true-color image of the Amazon rainforest’s vegetation shrouded by sheets of “popcorn” clouds. The clouds are distributed evenly across the forest but no clouds form over the Amazon River’s channels or associated wetlands.

Popcorn clouds—also called “fair weather clouds”—often form over thickly vegetated land, especially in the warmth of summer. To start with, heat from the Sun warms the land surfaces, which then warms the air directly above it. That warm air, rich in water vapor, then rises and condenses into clouds. In addition, plants use sunlight to fuel photosynthesis—a process that converts carbon dioxide and water into sugar and oxygen. As plants take up carbon dioxide, water vapor escapes the leaves. The newly-released water vapor also rises and adds to cloud formation.

Bodies of water, on the other hand, do not change temperature as rapidly; the water remains cooler even during full Sun exposure. The water does not heat up enough to significantly warm the air above it, preventing air from rising to make clouds.